


Haven't You People Ever Heard of Closing a Goddamn Door?

by GinnyRose



Category: The Last Hours Series - Cassandra Clare, The Shadowhunter Chronicles - Cassandra Clare
Genre: Accidental Exhibitionism, Accidental Voyeurism, Alastair Deserves Happiness, Alastair and Anna Are Friends, Alastair and Ariadne are Best Friends, Alastair is a Dramatic Bitch, Alastair is a Little Shit, Attempt at Humor, Canon Compliant, Cordelia is a Good Sister, Embarrassment, F/M, Fluff, Fluff and Humor, Happy Ending, Idiots in Love, M/M, Misunderstandings, One Shot, Post-Canon, Sibling Bonding, Spoilers, Walking In On Someone, gay and lesbian solidarity, lightstairs - Freeform, sibling dynamics, thomas is tired
Language: English
Status: Completed
Published: 2020-03-16
Updated: 2020-03-16
Packaged: 2021-03-01 03:48:57
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 15,383
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23168800
Author URL: https://archiveofourown.org/users/GinnyRose/pseuds/GinnyRose
Summary: Cordelia couldn't be happier that her brother found someone to love him as much as he deserved to be loved. She really, really couldn't. She just wished they weren't so affectionate all the time. Or that, at the very least, he would learn to close a door sometimes.Or: Four Times Cordelia caught Alastair and Thomas doing things she'd rather not see and one time they were at least cute.
Relationships: Alastair Carstairs & Cordelia Carstairs, Alastair Carstairs/Thomas Lightwood, Cordelia Carstairs & Lucie Herondale, Cordelia Carstairs/James Herondale
Comments: 25
Kudos: 343





	Haven't You People Ever Heard of Closing a Goddamn Door?

Cordelia adored her older brother. Certainly, he could be annoying. He was prone to dramatics and his tongue was sharp and rarely filtered. His bouts of overprotectiveness were hardly endearing, especially when directed at Cordelia’s intended. But he was the co-conspirator of her youth, her closest confidant in a time when they had both just been lonely children. He could be kind, inquisitive, sometimes even sweet. And when he loved, he loved fiercely, even if the person didn’t deserve it. Sometimes, especially when the person didn’t deserve it.

Cordelia adored her older brother, she really did. And she was happy that he was happy; she was positively thrilled that her brother had found someone who loved him in the same way Alastair loved. Fiercely, openly, unashamedly. Few things made her happier than glancing over and catching Thomas Lightwood looking at her brother with an expression of unguarded adoration. Whether her brother was patiently explaining the origins of a piece of art he enjoyed, softly gliding his fingers across the worn keys of their family piano he had taken to playing again, casually pulling out a spear from somewhere on his person despite the fact that spears _were not easily portable weapons_ , or tearing into someone with the fine-teethed finesse of someone with the uncanny ability of reading every single one of their faults at a moment’s glance, Thomas never looked at her brother with anything less than love in his eyes.

It was the least Alastair deserved, after everything he’d been through and all the hurt he’d endured, and Cordelia was really, truly, and completely happy for him.

She just wished they were a little less open about their – _affection_ for each other. Really, the longing and loving glances were sweet, but Cordelia didn’t need to see more than that. She really, really didn’t.

Unfortunately for her, Alastair appeared to be a very _affectionate_ person and he did not seem to care much where he showed said affection, as long as it was not outright in public. The first time Cordelia had ever seen her brother in a compromising situation, it had not been with Thomas Lightwood, and it had not been his fault. She had been eavesdropping and therefore it was her own fault that she had seen more than she had ever cared to see. With Thomas though –

She couldn’t shake the feeling that Alastair was torturing her on purpose. There was simply no way that a couple could be caught being amorous on more than one occasion without learning how a lock worked. Especially a couple whose existence could cause a fair bit of trouble amongst the stuffy, unforgiving members of the Nephilim if it were to be more widely known.

No, being caught once was an unfortunate accident. Being caught twice, sheer negligence.

Being caught _four_ times was nothing more than pure, purposeful spite intended to make someone suffer.

And Cordelia was _suffering._

The first time, Cordelia was nearly certain, had not been intended and was definitely more her fault than her brother’s. She hadn’t even known that he and Thomas had any sort of understanding – or whatever this type of relationship was called when it was between two men with no chance of marrying. She had expected that something of the sort might have begun – she was not blind and she could easily see the way Thomas had looked at Alastair when he thought no on was watching and, more importantly, she could see the way her brother had begun to look _back_ \- but she hadn’t known for sure. Which had resulted in a great deal of awkwardness all around and had begun the longest, most painful month of Cordelia’s _life_.

The first time went like this:

C _ordelia held tight to Cortana as she peered down from the banister carefully, her dressing gown swishing quietly in the still dark air of the house. It was late, far later than she should have been awake – she had already been asleep when she had heard a loud thump coming from the parlor. It had roused Cordelia immediately from her sleep and she had jumped up quickly to investigate._

_Her mother had retired to her room long before Cordelia had – the pregnancy, nearing its final stages now, was proving to be very taxing. Her father was gone to Idris for a few days– she had no idea what for and did not find she much cared. Alastair had still been out when she had retired herself, but he had surely made it to bed by now; she was mildly alarmed that she had not found him creeping out of his own room, weapon in hand. There was no one in her family who could be banging all around downstairs which left Cordelia with the deeply unpleasant idea that someone had somehow managed to break into her home. A someone that she had no choice but to deal with herself._

_With Cortana held close in one hand and a witchlight stone glowing in the other, she made her way slowly down the stairs and towards the parlor. She was surprised to see the soft glow of a gaslight inside the room and her movements slowed to a cautious creep. What kind of thief or murderer went to the trouble of lighting a lamp? It did not make any sense and if Cordelia had been thinking clearly and not through the muddled lenses of interrupted sleep, she might have smartly realized that no such criminal would light a lamp and that, coupled with her brother’s nonappearance upstairs after the loud thump, would have clued her in that this was not the type of noise that should be investigated._

_But Cordelia’s mind was sleep muddled and she wasn’t thinking clearly, and so she lifted her witchlight even further to help her peer through the gloom of the darkened entry way and continued foolishly towards the softly glowing parlor. She had expected to see some shadowy figure, perhaps a mundane with the sight who knew enough magic to get past simple security, perhaps a down-on-their luck Downworlder. Perhaps only one, perhaps more. She had expected to see the parlor upended in a search for quick valuables._

_She had very much_ not _expected to see Thomas Lightwood, without his jacket or waistcoat on, pressed hard against the parlor wall with her brother, equally as undressed, laying all his weight against him, one hand tightly clenching the front of his shirt to pull the other boy’s head down to meet his and the other hand somewhere much further south, fingers dipping slightly into the waistband of –_

_Cordelia couldn’t help but let out a mortified squeak, putting her hands to her eyes and dropping her witchlight and sword in the process. She could feel her entire face heating up as she took several hurried steps back. She could hear some very creative cursing streaming from her brother now as well as a loud bang that could only have been Thomas Lightwood slamming his head into the wall. It sounded rather like the thud that had brought her out of bed and it was with no small amount of horror that she realized the sound she had heard was her brother throwing another man against their parlor wall in the midst of a passionate embrace._

_Cordelia had been through this before but at least with Charles it had seemed far less – further on in the process and there had at least been some talking. It did not look like much talking had been taking place between Thomas and Alastair at all – it would be hard to get any words out, when one’s mouth was so thoroughly occupied, after all. She hadn’t even known that Thomas and Alastair had become so intimate with one another. She had quietly suspected there was something there in their long gazes but she had no inkling that it had bloomed so rapidly that they were now comfortable defiling each other in the Carstairs family home._

_Did it even count as defiling when it was two men? Were both doing the defiling equally or was there a hierarchy in which one was stealing the other’s virtue but not the other way around?_

_Did she have to worry about Thomas Lightwood stealing her brother’s virtue? Did her brother even still have his virtue?_

_Did she have to worry about her brother stealing_ Thomas Lightwood’s _virtue?_

_Could a man even lose his virtue to another in the first place? Or was that something that only applied to girls?_

_Could a girl lose her virtue to another girl, even? Or did it only count with a man?_

_Cordelia was spiraling. She knew she was spiraling. Had she been smart and not entirely coming unwound, she would have dashed back up the stairs and saved the whole lot of them an excruciating encounter. But she was too busy silently losing her mind to move from her new spot in the dark entrance way and back into the safety of her bedroom._

_"Cordelia!” Alastair’s voice, laced with clear irritation, burst through her spiraling thoughts and Cordelia let out another inelegant squeak in response._

_"I wasn’t eavesdropping!” She said, her voice suspiciously high and muffled by her hands. She didn’t dare drop them – she rather thought she’d never be able to look her brother or Thomas in the face again. “I promise I didn’t mean to eavesdrop! I heard a banging and I thought there might be an intruder!” her voice was rambling and she knew quite well that if her brother didn’t stop her soon, she was liable to begin rambling uncontrollably and not stop until the sun came up._

_"Oh for goodness’ sake, Cordelia, drop your hands! We’re decent!” Alastair snapped, his voice dripping now with impatience. Cordelia didn’t really think anybody whose hands were where Alastair’s were just a moment ago had the right to call themselves decent but she obediently shifted her fingers so that they were splayed across her face and she could peek out from the gapes between them._

_Alastair was standing in front of her, with Thomas looming behind over his shoulder. Neither man had put their waistcoats back on, although Thomas seemed to have quickly grabbed his jacket to hold in front of himself. Both their heads of hair were rumpled beyond repair but they at least seemed to be wearing the basics. Alastair was staring at her with a look of pure annoyance while Thomas seemed far more interested in the wallpaper behind her than her actual face, a look of vague horror and mortification etched into his fiery red cheeks._

_Deciding that they appeared as decently as two men caught in the throes of passion could appear, Cordelia obediently dropped her hands down to her sides. It was then that she realized that, as she was standing in front of her brother and friend in nothing more than her bed clothes and a hastily put on dressing gown, she was the least decently dressed person in the entire group and she felt a fresh rush of embarrassment warm her face._

_Alastair, undoubtedly catching onto the new batch of mortification, waved an impatient hand at her. “You’re my_ sister _and, regardless, if it isn’t clear to you by now that neither Thomas nor I care one bit for a girl’s attire, you’re woefully blind. There’s no need to concern yourself with your modesty right now.” Thomas’s already red cheeks turned even brighter behind Alastair’s shoulder as he let out an undignified squawk that Cordelia only barely restrained herself from echoing. Her brother was being shockingly blunt._

_Alastair didn’t seem to care what effect his words were having on Cordelia or Thomas as he scowled at his sister, one hand lifting to push his mused hair back from his face as he impatiently spoke, “What exactly possessed you to come to the parlor? I couldn’t make any sense of your words behind your hands.”_

_Cordelia grabbed at the edges of her dressing gown and twisted her fingers into it. “I heard a noise,” she admitted, not quite meeting her brother’s eyes and ignoring another embarrassed squawk from Thomas. “I thought it might have been an intruder.”_

_"In our_ warded _house? You thought someone broke into our warded house and decided to come down and investigate by yourself?” Alastair demanded incredulously and Cordelia felt a rush of anger alongside her embarrassment._

_"As I am_ trained _to do! I do very much apologize if I associate a loud crashing with potential danger and not my brother having –“ she paused, stumbling for the proper words, “relations with one of his good friends!”_

_"_ Relations _?” Alastair repeated as Thomas let out a very loud, very horrified groan. “Cordelia, we were just kissing – it’s hardly a matter that severe!”_

_“Explicit kissing!” Cordelia hissed back stubbornly, moving to cross her arms over her chest. “And why do you insist on inviting your –“ what was the word for Thomas’s relationship to Alastair? Was there a word? She would have to ask somebody to be sure – Matthew or Anna would certainly know. “significant friends into the parlor for such activities?”_

_"Because I_ foolishly _didn’t believe my sister would be coming down to interrupt!” Alastair retorted, throwing his hands out in irritation._

_"If you don’t want to be interrupted, don’t be so loud!” Cordelia responded back. “Or at least invite him into your bedroom!” Thomas seemed to be whispering under his breath now, something that sounded suspiciously like a prayer to be taken away, but both Carstairs siblings ignored him. “Do you think I want to be a witness to such matters?” She demanded._

_“I am beginning to find it rather suspicious that you always seem to miraculously appear at the most inopportune times!” Alastair shot back and Cordelia was beginning to remember all too well why she often found her brother so annoying._

_“Well, I assure you, I do not want to be privy to my brother losing his virtue or taking somebody else’s!”_

_“Losing my_ virtue _?” Alastair spluttered indignantly._

Had Cordelia not been seething at the time, she might have realized she was entering very dangerous waters. But she had been angry, and like many tragic heroines before her, her anger had made her blind.

_“I do believe that is the term for such affairs!” She responded back, heedless to the precipice she was dangling on. “Or is it called something different when it is between two men? Either way, I assure you clearly, I want no part of it!”_

_"You don’t even know what you are talking about!” Alastair seethed as Thomas wordlessly turned and knocked his forehead rather hard against the wall behind him._

_"I’m not so naïve that I do not know what an intimate moment looks like, Alastair!” Cordelia said, uncrossing her arms and placing them on her hips. “And I’m beginning to wonder if it is not you that enjoys being caught at them!” She didn’t know what possessed her to say it – probably the smarting embarrassment that still stung from his own accusation against her– but it could not be taken back, even if she wanted it to be. It was out there, between them, and there was no turning back. She had fallen fully off the precipice as she turned and stormed back up to her room without another word._

Had she known what Alastair would begin planning as his payback, she would have fallen to her knees to apologize. She would have groveled, might have even forced a few tears outs.

But she had not known and thus, the longest, most scarring month of her entire life began.

The second time occurred only a few days later and it happened in the most shocking of places:

_Cordelia had meant to apologize to her brother the morning after their altercation. It really had been her fault, overall, that she had interrupted her brother, and she had said such scandalous things that they brought warmth to her cheeks just thinking about it. It would only be proper to apologize, even if she felt like Alastair should also issue an apology of his own._

_But Alastair never gave her the chance. She had expected him to be furious at her, but her brother greeted her with the same warmth as he did their mother over breakfast the next morning and had then disappeared before she could confront him. When he had returned, in the early afternoon, he was surprisingly cordial and had even offered to gift her with a new stele. He seemed, in short, determined to pretend that the entire evening had not happened. While Cordelia felt that apologizing would have been the right thing to do, she had to admit to herself that forgetting it had happened at all was a far more ideal course of action._

_Had she known what was in store, she would have cornered her brother and forced him to listen to the most heartfelt of apologies to ensure he would feel too guilty to go through with his plan. But she didn’t know – didn’t even have an inkling – and so she let it slide and they fell back into the comfortable rhythm of teasing and protecting each other. Their relationship was better than it had been since Alastair had left for the Academy and Cordelia was so happy that their spat had not broken it that she did not consider the fact that their peace wasn’t built to last._

_The day of the second incident dawned with a sense of excitement. It was the day of her and James’s engagement celebration – their second one, technically, but the first sincere one. After they had broken Grace Blackthorn’s bracelet – and the enchantment within it – the truth about James’s and Cordelia’s arrangement had been made known to a select few more people; namely, their parents. Will Herondale had handled the news about his eldest child being placed under a curse for years as well as anyone had expected – which is to say, not well at all – and had seemed downright heartbroken that their soon-to-be marriage was, by all intents and purposes, a complete fraud, a sentiment shared by both Tessa Herondale and Cordelia’s own mother._

_When James had rushed to say that their engagement, while initially only meant to preserve Cordelia’s honor, had indeed become quite real to the both of them once the curse had dissipated for the second time, it had been as though a heavy weight had lifted off all the parents. Will Herondale had immediately insisted on a second engagement celebration under the pretext that, since Cordelia’s father hadn’t been able to make it to the first, another must be held. As most Shadowhunters had wrongfully assumed that the party was merely a pretext for tastefully celebrating the defeat of Tatiana Blackthorn and Belial, they allowed it to go on as planned without question. And now Cordelia would be able to dance with her fiancé once more and know that it was real this time._

_It was an amazingly buoyant feeling and it was with palpable delight that she took her brother’s arm and graciously stepped down from their carriage and towards the London Institute that night. She was dressed in a beautiful gown of deep wine, an extravagant engagement gift from Anna, and wouldn’t deny that she and her brother both looked splendid as they walked together into the Institute. Their mother, who had begun to tire easily in these last months of her pregnancy, had arrived at the Institute earlier in the accompaniment of their – newly returned and blessedly still sober - father, in a separate carriage borrowed from the Herondales so that they could retire easily without forcing Alastair and Cordelia to also leave early._

_It was amazing how much the promise of her marriage had made their mother soften her vigilance. Cordelia was not about to question her good fortune tonight and neither, evidently, was Alastair even though he was still wary of their father’s purported abstinence from the drink. They entered the London ballroom to a party already in full swing and it was with a few polite greetings and a pleased grin in the direction of one Thomas Lightwood that Alastair dropped Cordelia off into the company of her soon-to-be in-laws._

_Will was all ecstatic grins and sweeping hands as he professed an impressive number of compliments on Cordelia, ranging from how the dark red of her dress perfectly complimented the golden hue of her skin to how beautifully she had spoken at the last Clave meeting. Tessa, always the soft calm to Will’s exuberant storm, was all sweet smiles and gentle laughs as she pulled Cordelia into a gentle hug before directing her further into the room. Cordelia let the rush of the words flow past her with a small smile, her eyes carefully scanning the room._

_She didn’t have to wait long before she spotted her query – James, stunning as always, was already approaching her, a smile on his lips and a brightness in his eyes. It was marvelous, truly, how quickly one’s attention can focus on just one thing – the moment she made eye contact with her fiancée, everything else faded away. She hardly noticed that she had shifted her body away from Will and Tessa or that Will’s bright chatter had faded into a knowing silence as he caught sight of what had stolen her attention so soundly. All that mattered, in that brief moment, was James – her James – coming towards her with a soft, loving smile._

_When he asked her for a dance , all proper politeness marred only by a devilish twinkle in his golden eyes, Cordelia didn’t hesitate. It didn’t matter that it was a waltz and she could hear her mother’s warning words about inappropriate dancing in the back of her mind, it didn’t matter that she knew they were drawing the attention of many others, all intent on watching the couple they were officially celebrating, all that mattered was the feel of James’ body lightly pressed against hers and the warmth of his hand in hers._

_Cordelia didn’t know how much time passed in the flurry of dances that followed – she remembered giggling through a spirited dance with a beaming Matthew after she and James had separated before suffering through several painful toe smashes with a mildly distracted Christopher. She remembered coasting through a very polite dance with Thomas that involved little eye contact and a lot of warmed cheeks – they had not seen each other since Cordelia had caught him and her brother and although they were both eager to pretend nothing had happened, the awkwardness was palpable – before embarking on a series of dances with men she knew only vaguely and whose names often escaped her._

_Words of congratulations had been abundant, particularly from the few that knew the engagement had only become real rather recently, and the general air of the party – nearly riotously celebratory because of their recent victory – was uplifting and contagiously happy. Cordelia’s mind was filled with a pleasant, almost giddy sort of fuzziness as she broke from the dancing with a polite word of thanks to her last partner and headed to where Lucie was sitting next to a small group of other unmarried girls._

_“Daisy!” Lucie called happily as she approached and Cordelia smiled in return as she took the offered seat next to her best friend. Their parabatai ceremony was fast approaching – it had been postponed due to the craziness that had befallen the London Institute in the past few months but was now scheduled to take place in just a few weeks’ time – and Cordelia could see a small bound book on the ceremony discreetly tucked away on Lucie’s lap. She knew the other girl had already read everything she could about parabatai but it never hurt to brush up on it more. Especially because Cordelia had it in good authority that the Beautiful Cordelia would also be going through a similar ceremony in the upcoming chapter of her saga and Lucie was nothing if not a devoted storyteller._

_The girls fell into a fast conversation, easily droning out the rest of the room around them in favor of each other. Had this been just a few months ago, Cordelia would have balked at ignoring the party-goers around her – she would have been making the rounds, trying to get in with people who could help her father or her mother would have been pushing her to try and draw the attention of eligible bachelors and possible influential friends in a discreet, modest way. Now though, with her father back home and working hard to mend his relations with his children, wife, and fellow Shadowhunters and with plenty of good friends Cordelia knew she could count on, she found she didn’t much care what others thought of her manners and she had no problem getting lost in a spirited discussion of the latest adventures of the Beautiful Cordelia._

_So engrossed in their conversation, Cordelia nearly missed her mother and father coming up to them. She probably would have missed them entirely and been forced to endure a light scolding about how a girl “should always be aware of her surroundings” from her mother had she not caught sight of her mother’s ample belly from the corner of her eye and turned just in time. Older woman or not, no one could deny that her mother was handling her pregnancy with the same extensive grace that she handled every other part of her life. She was dressed in a loose, flowing gown of deep blue and she was smiling without any sign of the fatigue she was surely feeling. Cordelia’s father stood just behind her, a smile of his own on his face with – mercifully – no drink in sight._

_“I am glad that you are enjoying yourselves, girls.” Her mother said, no hint of rebuke in her voice. It was not that long ago where sitting out in a celebration such as this would have earned Cordelia several stern words, but pregnancy and the difficulty of the last few months had softened her mother in ways she had never expected. The approaching marriage helped, but Cordelia liked to imagine that her mother’s new laxness was also a sign that she was happy again, with both her nearly grown children in good standing, her husband more present than he had been in years, and no one currently plotting the demise of all Nephilim. “And I’m happy we were able to celebrate your and James’s engagement with your father here.” Cordelia could hear the meaning hidden neatly in her mother’s words and she beamed at her._

_“But I’m afraid it’s getting a bit late for me and so your father and I will be retiring early. We’ve already spoken with the Herondales and they’ve generously agreed to allow us one more night with their carriage, so we shall be taking it after we’ve said our goodbyes and will leave ours for you and Alastair to take later this evening.” Her mother finished. Cordelia nodded in understanding._

_“I’ll see you at home then, Mâmân. Papa.” There was still some awkwardness, between her and her father, that made it hard to talk even in public, but she included him anyways. He was making an effort and it was only fair Cordelia did the same._

_“Good evening to you as well, Lucie,” Her mother added and Lucie beamed at the both of them._

_“And you as well Mrs. Carstairs, Mr. Carstairs!” She said with her usual amount of enthusiasm._

_“Do tell your brother we’ve left, if you can find him. I couldn’t figure out where he’d gone to.” Cordelia’s mother added before turning away, a small frown temporarily marring her happy expression. Cordelia barely resisted the urge to look around the ballroom, not for her brother, but for Thomas. If Alastair had disappeared off somewhere during the thick of the party, she couldn’t imagine it wouldn’t have been to have a private moment with Thomas and there was no way Cordelia was going to let even the slightest hint of that fact get back to her mother. She didn’t think their mother would reject Alastair because of his preferences, but she was not going to be the one to test the theory._

_“I will, Mâmân.” She promised while secretly vowing to do no such thing. She was absolutely not going to put herself in the position of hunting down her brother and accidently finding him in another illicit position with Thomas Lightwood. Once was more than plenty to last several lifetimes, truly._

_“Strange that Alastair’s left the party,” Lucie commented the moment Cordelia’s parents had disappeared back into the crowd to say their goodbyes, looking around the ballroom for any sight of her future parabatai’s brother with curious blue eyes. “Perhaps we should investigate?” Cordelia barely resisted a slight shudder at the idea._

_“We really shouldn’t.” She told her friend immediately, perhaps a tad too firmly. Lucie rounded on her with an expectant look on her face but Cordelia refused to elaborate. It wasn’t her secret to reveal and she would rather not explain how exactly she knew that trying to find her brother in this moment was a very, very bad idea. Lucie usually would have pried but there must have been something in Cordelia’s expression that warned her off because she seemed to dismiss it easily and turned to the book half-forgotten on her lap._

_“I found this most delightful drawing I’ve been meaning to show you! I’ve tucked it into here for safekeeping,” Lucie told her, easily switching subjects, as she flipped open the cover of the book. To Cordelia’s surprise and Lucie’s dismay, there was no such image tucked inside. With a frown, Lucie flipped through the pages all the way through to the back cover with no image in sight. “Oh, I can’t believe I lost it! James is going to be so angry!” Lucie groaned, closing the book with an uncharacteristically harsh snap. Cordelia frowned in confusion._

_“Why would James be angry?”_

_“Because I took it from his room in the Devil’s Tavern when I went to steal this book.” Lucie admitted candidly, flipping the cover open again in some vain hope she could magically summon the lost image._

_“You_ stole _that book?”_

_“Well, James and Matthew have been parabatai for ages, it isn’t like he needed it anymore!” Lucie responded and Cordelia had to quickly bite back a smile. It was a very Lucie response but she didn’t think James would see the amusement in it, once it got back to him that his little sister had pilfered his nearly sacred bookshelves._

_“Where did you last have it? Maybe we can find it before James realizes it’s missing?” Cordelia suggested. Lucie pondered for a moment, then shot up with a speed that nearly knocked her chair down. “I was looking at in the carriage on the way back! I must have dropped it in there!”_

_“The carriage my parents are borrowing?” Cordelia asked, instinctively standing up so that Lucie did not attract too much attention for her abrupt movements. Lucie nodded._

_“We’ve got to go look for it!” She said and Cordelia nodded immediately._

Had they paused to think for even just a moment, they would have come to the realization that there was no way for James to discover the missing drawing that very night and Cordelia would have had access to the carriage and been able to search for it in the light of day. Had they paused, disaster might have been averted.

But they hadn’t stopped to think and instead, had plunged headlong on a dark path that would lead only to disaster and misfortune.

And lots and lots of fresh mortification.

_The girls slipped from the ballroom with ease and made their way quickly to the entrance of the Institute. The carriages were all lined up neatly around the front of the Institute, their horses neighing softly and padding the ground absently as they patiently waited for their masters to return them. It was a tad too dark to make out the individual carriages easily but Lucie, ever prepared, pulled a witchlight from a hidden pocket of her gown and illuminated the carriages with its soft glow._

_“There!” Lucie whispered, spotting her family’s carriage easily in the witchlight. Cordelia was not sure why exactly they had decided to be quiet – there was no one around to catch them with everyone inside enjoying the celebration – except that the quiet darkness around them seemed to require low volumes -_

Perhaps if they had not fallen prey to night’s strange magic, they might have escaped tragedy. But they had fallen and tragedy had quickly followed them down -

_and so they approached the carriage with unnecessary quiet and silently, carefully opened the carriage door –_

_Just to be met, quite suddenly, with the sight of her brother straddling Thomas Lightwood’s lap on the carriage seat, their faces mashed quite efficiently together and their outermost layers of garments thrown about the small space. Cordelia had just enough time to witness the horror that was Alastair’s hands, tightly wound in Thomas’s hair, lightly pulling on the dark strands in a way that brought an unholy groan from the other boy and caused him to tighten his hold on Alastair’s hips and somehow pull him even_ closer _before her senses caught up and she slammed the carriage door closed with a small cry of surprise and horror._

_The yelps and curses that erupted from inside the carriage were clear indicators that the boys had noticed the intrusion but Cordelia hardly had time to care about that as she immediately turned towards Lucie, both her hands still pushing against the door to keep it closed. Lucie looked truly and completely shocked with her blue eyes blown wide in surprise and a hand over her mouth to curb any sounds. Cordelia had no idea what to say. She didn’t believe that Lucie would think poorly of her brother for preferring men to women – she certainly had no qualms with her cousin Anna or Matthew – but she did not know if Lucie would approve of Alastair – with all his rough edges and sharp words – being with sweet, gentle Thomas. But Lucie seemed more surprised than upset and it only took half a moment for her surprise to give way to a slew of words:_

_“_ Thomas and Alastair _? Did you know about this, Daisy? Do you think people often use carriages for illicit activities or is just them? Do you think they’d mind if I asked? It could be a good addition to my story, I feel like it’s been missing some good romance and as I continue to be_ woefully _unseduced I really –“_

_“Lucie, now is not the time.” Cordelia hissed. Part of her was glad that her friend seemed to be accepting her brother and Thomas’s relationship with startling quickness, but a larger part felt like they had much bigger things to deal with. Like avoiding being murdered because this incident marked the second time she’d walked in on her brother with Thomas and third time overall and goodness, she was never going to get the sound of them together out of her head – she would have to deafen herself, it was the only way to rid herself of Thomas’s soft groan -_

_“Cordelia,” Lucie said, voice suddenly sharp. Cordelia glanced up at her friend, surprised. She perhaps had spoken a little roughly but surely Lucie wasn’t_ angry _at her given the situation at hand. But Lucie didn’t look mad by any means – instead, she appeared to be positively worried as she looked up at Cordelia with wide blue eyes. “Aren’t your parents taking this carriage home? Soon?” Cordelia’s own eyes widened with realization and she barely resisted letting out a word she’d heard her brother utter in some of his worst moments._

_She was pretty certain her mother had some inkling – why else would she not be pushing Alastair to marry a girl from a good family, after all? But there was no way her father knew and there was no way Alastair would want him to find out in the near future, if ever at all. And especially not in the_ very near _future, after he’d done his best to defile the Herondale carriage. Cordelia didn’t have a choice – she would have to warn her brother._

_With the air of someone walking to the gallows, Cordelia swallowed a bracing breath, slammed her eyes shut, and swung the carriage door open. There were more squawks and the rustle of fabric that suggested the two men had been in the middle of redressing when Cordelia had thrown the door open once more, but she paid them no mind and quickly spoke:_

_“Mâmân and Papa are coming soon to take this carriage back to the house. Hurry and get dressed before they finish saying their goodbyes.” She slammed the door before either man could say anything._

_“If you see a drawing on the floor or anything, please bring it out for me!” Lucie called through the door, continuing to be shockingly unbothered. Cordelia envied her cool. Her entire face felt like it was burning as she quickly took hold of her future parabatai’s sleeve and began dragging her back up the steps before her brother or Thomas could respond._

_She couldn’t believe this. Of all the places in the entire Institute, her brother had decided to have a clandestine meeting with his paramour in a carriage. There were empty bedrooms spread all throughout the Institute that would have allowed for far more privacy and would have – probably, Cordelia did not have nearly enough knowledge on how such actions took place between two men to know for sure – afforded the pair far more comfort and still, they had chosen a_ carriage _._

The one carriage that Lucie just so happened to lose an important drawing in. The one that Cordelia and she had chosen to comb through at exactly the wrong moment that night.

If Cordelia had been thinking clearly at the time, she would have noticed that both the placement and the lack of yelling on her brother’s side were equally suspicious. But Cordelia had been too busy contemplating the best poisons to cause short term memory loss in both her and Lucie to pay any thought to the odd circumstances surrounding her second involuntary encounter with her brother and Thomas’s amorous relationship.

By the end of the third time, however, Cordelia had learned enough to begin to be suspicious.

_The day of the third incident started off innocently enough. A full week had passed since the celebration and both she and Alastair had evidently decided nothing had ever happened. In fact, the only indication her brother, usually quick to anger when he thought Cordelia had done something meddling, even gave that he remembered the event was the presentation of Lucie’s drawing – a very detailed, rather old but beautiful depiction of a parabatai ceremony - to Cordelia at breakfast the following morning._

_Cordelia had squeaked out a small, surprised thanks before secreting the image away and had pointedly refused to meet her mother’s slightly suspicious, questioning glances throughout the rest of the meal. She had meant to confront her brother after the meal but he had brushed off her attempts with a far-too-casual smile and the announcement that, as he had patrol that evening, he would be leaving to attend some personal matters that morning. Cordelia had little doubt as to what “personal matters” could have meant and had sat back in her chair with a grumpiness that had her mother outright glaring at her over a jam jar._

_She had allowed the conversation to drop after only one failed attempt for two very good reasons: she really, really did not want to discuss it with her brother and because, surely, both she and Alastair had learned their lessons and she would never catch him again. It was a nonissue; it didn’t need to be brought up again._

How naïve she really, truly had been to believe that.

_Alastair lured her into a false sense of security, throughout the next week. He continued to be perfectly nice, as though nothing at all strange had happened between him, her, Lucie, and Thomas. He’d even joined in on a picnic in the park with Lucie and the rest of the Merry Thieves just two days after the celebration. Thomas had been a little awkward at first, his cheeks flushing whenever he caught sight of Cordelia looking at him, but he’d warmed up quickly once it became clear that Cordelia was absolutely_ not _about to speak about what transpired. She had also convinced Lucie, who seemed to find the whole matter entirely humorous and not at all horrifying, not to bring it up and so the rest of their group were able to be blissfully unaware as they enjoyed their picnic._

_Although she had caught Matthew giving Thomas and Alastair a contemplative look when the latter had sat a little too close to the former for strict propriety. Matthew and Alastair had, at some point in the last few months, managed to reconcile in a way that meant, even if they weren’t quite friends, they were capable of being perfectly friendly but Cordelia still carefully tucked the look in the back of her mind. Even though she was friends with Matthew, she wouldn’t allow him to speak ill of Alastair and Thomas’s relationship, if it came down to that. As much as she loathed having far too much personal knowledge at the intimate, amorous portions of their relationship, Cordelia was over the moon that Alastair had found someone to care about him the way he deserved to be cared about and she was not about to allow anyone to get in the way of that._

But nothing bad had happened that day, or the day after that, or the one after that, and just as the spider weaves its web thinly so as to lure in unsuspecting flies, Alastair lured her back into normalcy carefully and skillfully. And then, just when she thought that, at last, things had returned to normal in their household – Thomas could even look her in the eye again without blushing faintly – Alastair struck again.

_Cordelia had spent the morning of the third incident with Lucie at the Institute, preparing for their upcoming ceremony which was to be held on the last day of the month. Cordelia had been rather distracted, despite Lucie’s and her father’s - Will had taken it upon himself to prepare them for the ceremony just as he had done for James and Matthew before them - best efforts, however, because her mother and father had gone to the Silent City that very same morning. It had been planned and nothing unexpected– due to her mother’s age and the stress the last few months would have had on anybody, it had been decided that Sona Carstairs would bring her third child into the world inside the safety of the Silent City, where the Brothers could easily be at hand for any surprise complications. Cordelia rather suspected that cousin Jem had pulled a few strings – or whatever it was that Silent Brothers could do to sway the others – to make it so, but she was hardly about to question anything that was designed to make her mother’s upcoming labor easier and less dangerous._

_Cordelia’s mother had told her multiple times in the days leading up to the visit that there was nothing to worry about and logically, Cordelia knew that to be true. Nothing had happened so far in the pregnancy to cause any real concern and at this stage, the only hurdle left was the actual labor. Something which her mother had gone through twice already with no problems whatsoever – as she was always quick to remind her daughter whenever Cordelia began to express excess anxiety. But her mother’s assurances and her own logical side was not enough to keep Cordelia from fretting and it was with the kind air of someone who knew what it was like to worry without much cause that Will had his carriage readied to take Cordelia home so that she could be there when her mother and father returned._

_Lucie had offered to accompany Cordelia home but she had declined after only a moment’s deliberation. She wouldn’t be much company while she worried and she had already decided that she was going to work on clearing out the lower floor of their home and bringing out all the new decorations her mother had purchased for the parlor and dining room – a task that her mother had been working on ever since they had decided to make London their permanent home and one that Lucie would have hated to participate in despite all protests she would have undoubtedly made to the contrary._

Reflecting back, Cordelia was glad in her decision not to bring her friend. As much as she cared for Lucie, she had no doubt that her friend would have only made the situation at hand far worse. And far more embarrassing.

_And so it was with a small smile and several assurances to both Lucie and her father that she would be quite alright that she set off in the Herondale’s carriage. It truly was a testament to the normalcy of the last week that Cordelia hardly thought about what her brother and Thomas had gotten up to in the space as she sat in it._

_It did not take long at all for Will’s driver – a middle-aged mundane named Cyril that had been with the Institute for ages and who was always very kind and perhaps a bit too understanding of the younger Herondales antics - to guide the horses to the Carstairs home. In truth, the horses had come to their house so often and were such intelligent creatures that Cordelia would not be at all surprised if she found out they could make the journey all on their own and she made sure to give the one closest to her a grateful pat after she had thanked Cyril for bringing her home._

_Cordelia made quick work of the downstairs once she had gotten inside. It helped tremendously that her mother, herself, and their maid – a lovely mundane girl with the sight named Elsie Taylor – had already accomplished most of the clearing out. They had been planning to finish that weekend, when Elsie returned from her visit to her family, but Cordelia wanted to surprise her mother with the task completed. And the constant motion of moving things her mother wanted gone down to the cellar – her father had already hired several workmen to come and collect the things in a few days’ time – helped Cordelia keep her mind off the Silent City and her mother within it._

_It took only half an hour to finish making space for the new decorations and the family heirlooms that had yet to be placed and Cordelia was feeling far better than she had back at the Institute. Her mother would be so happy coming home to the bottom floor of the house finally finished and Cordelia’s worries had been replaced with a low drum of excitement. Cleaning and organizing were some of her least favorite chores but there was still a certain air of satisfaction around her as she headed up to the second floor, on the hunt for some decorations she had seen in what was to be the nursery._

_Cordelia had, for the past hour, been working under the assumption that she was the only one in the house. Both Elsie and their cook - a vivacious, friendly mundane girl with the sight named Imogen Carter - had been given a week off to visit family in preparation for when they would be needed more around the house while Cordelia’s mother recovered from the birth and Alastair had left early to attend to some errands for their father. He had said he would be paying a visit to an old Academy friend afterward, so Cordelia had reasonably assumed he had still been out when she got home and he had obviously not slipped in while she had been working her way through the dining room and parlor -_

Had Cordelia known that this was not true, she would have proceeded up the stairs and past her brother’s bedroom with a great deal of more caution -

_And so, when she rounded up the stairs, she was surprised to see the soft glow of sunlight coming from the partially opened door of her brother’s bedroom. Alastair_ always _closed his door, a long-term habit from when Cordelia used to sneak in and steal his things when they were children, and it was incredibly odd to see it open now._

Had Cordelia been properly suspicious, she would have noted that Alastair would _never_ have left his door open after leaving the house even though she had largely outgrown childish bouts of petty theft and would have smartly walked right past the room on her way to the nursery _._ But alas, she had fallen fully into the trap of normalcy and she had not picked up on the oddity.

_Cordelia headed straight for Alastair’s door to shut it for him but was blessedly stopped from walking close enough to peer into the room by a noise coming from within it. Or perhaps it was cursedly – for Cordelia recognized the noise, even though she had done her best to permanently wipe it from her mind._

_The noise that had escaped from her brother’s room was the unmistakable sound of one Thomas Lightwood softly groaning._

_Or at least, it had_ better _be Thomas Lightwood – otherwise, she would be having_ several _talks with her brother._

_Cordelia knew enough now not to investigate any noise emitting from anywhere but that didn’t mean she could magically block the sounds and the unmistakable sound of the heavy bedframe creaking was enough to make her entire face feel as though she had been thrown into a fire head first. Part of her was screaming to just walk away and pretend she didn’t hear anything – it would be far better for everyone involved to just ignore it. And she very much enjoyed being able to have eye contact and hold conversations with Thomas. And they had at least gone into Alastair’s bedroom, this time._

_Alastair’s bedroom that he had just happened to leave open when Alastair never did that._

_For the first time, Cordelia felt less mortified and more suspicious._

_Her brother was careful enough that he was able to carry on an illicit, secret relationship with Charles Fairchild for_ years _and she’d only caught them once – but suddenly she was finding him with Thomas all the time? Something wasn’t right about that._

_But then again, was her brother petty enough to cleverly orchestrate rendezvous with his lover that just happened to coincide to times when Cordelia was the one most likely to find them?_

_Yes. Unequivocally yes._

_But then again, surely Thomas wouldn’t do something like that? Thomas who had only just started looking her in the eye again and always seemed to have a permanent, faint flush on his cheeks?_

_There was no way he would agree to something as ridiculous and mortifying as this, no matter what her brother wanted._

_Unless, of course, Alastair proved to have some very convincing arguments about why they should do it._

_Cordelia didn’t want to think about_ that _. She refused to think about that. She had more pressing things to deal with, like the fact that, regardless of whether or not it was intentional, her brother’s door was open to a very private scene and their parents were due home rather soon. Cordelia did not know how long such affairs took, but she couldn’t allow her brother and Thomas to risk it. Especially on the chance that this was, once more, just an unfortunate accident._

_Bracing herself, knowing that announcing her presence in any way was going to upset the delicate normalcy they had finally been able to reestablish, Cordelia closed her eyes tightly, stepped towards the door to rap on it loudly and called out, “the door is open, you reckless idiots!” Then she turned without another word and continued her journey to the nursery, pointedly ignoring the loud crash that sounded suspiciously like two nearly grown men falling off a bed._

Cordelia had once more given her brother the benefit of the doubt during this third incident. By the fourth, however, she just _knew_ he was absolutely doing it on purpose.

_Cordelia didn’t try to confront her brother after the third time. She knew it wouldn’t help anything and so when they came shuffling downstairs, Thomas red-faced and Alastair cool as ever, she simply gestured to the decorations she had brought down and pressed them into helping her finish the project. If they were going to insist on forcing her into embarrassing situations, they could at least do some work to make up for it. Even if she couldn’t quite look them in the eye as they passed her the silk flowers._

_The rest of that week passed with both Carstairs siblings purposely ignoring the glaring elephant in the room. It became apparent to Cordelia, however, that sometimes when her brother didn’t realize she was watching, he seemed to be expecting something from her. What exactly he was waiting for, she didn’t know and so she went ahead and ignored that too. In her opinion, if Alastair had something to say about the whole situation, he could start the conversation because she certainly didn’t want to dwell on anything related to it._

_But ignoring it didn’t mean Cordelia was naïve enough to drop her guard down again. There was still the nagging suspicion in the back of her head that Alastair was somehow orchestrating all of this on purpose and even though Lucie – the only person Cordelia could confide in about these matters as she had also witnessed Alastair and Thomas – seemed to think Cordelia was overthinking the situation, Cordelia wasn’t about to be caught off guard again._

Which was why, just a few days after the third incident, she had found herself quietly cursing her fiancé. In fairness to him, he had not yet known to _never_ investigate an odd noise in the Carstairs home, which is what had led them into the most awkward situation yet.

_The day had started off well enough. Breakfast was a pleasant, if quiet, affair and it had been followed by Cordelia and her parents leaving for the day – Cordelia to the Institute to train, her parents to pay a call to the Lightwoods while Alastair had elected to stay home in order to finish some reports from the previous night’s patrol. Cordelia had been skeptical of her brother’s intentions up until she watched him sit down with pen, ink, and several sheets of loose paper in the small study off the parlor. Not even Alastair could find a way to turn fieldwork reports into an illicit encounter._

_At least, she didn’t_ think _he could. Alastair seemed to be a connoisseur of improper activities, so it wasn’t completely outside the realm of possibility._

_Cordelia chatted with her mother amicably all the way to the Institute – what with the baby fast on its way, her parabatai ceremony around the corner and her wedding almost right after, on top of the increased duties she had now as a Shadowhunter who had been in the thick of the struggle with Belial, there hadn’t been a lot of time to just sit and speak with her mother. It was a refreshing feeling, even with things still being rather awkward around her father, and Cordelia was in high spirits when their carriage pulled up in front of the Institute._

_Her day only improved at the sight that awaited her in the weapons room after she’d changed into her gear. James, who she had been unable to see over the last few days due to the fact that Matthew’s mother had asked them to visit the Cork Institute for her, was waiting beside Lucie, dressed in dark gear and idly twirling a dagger between nimble fingers. He shot her a wide smile when she came in and when all three of them set of to the training room, weapons quickly selected from amongst the wide variety the Herondales kept, he walked close enough to her that their fingers lightly brushed._

_It wasn’t much but with the memory of several of their own private encounters never far from her mind and the promise that soon they would be able to do much more than brush their fingers together, it was enough to send a delicious shiver down her spine. A great deal of the time – particularly whenever she was around James, Cordelia felt that her wedding couldn’t come soon enough and it was in these moments that she could best understand her brother and Thomas’ frequent displays of affection._

_Sometimes, Cordelia felt that it would be much easier to be a man and not have to worry nearly so much about her reputation._

_They reached the training room quickly and Cordelia banished her thoughts with a gentle shake of her head. She was not a man and she could not be nearly as carefree about her honor as Alastair or Thomas or any of the other boys in the Merry Thieves could be. And besides, she had more important things to focus on at the moment._

_Like her best friend coming at her with a freshly sharpened axe, appearing to do her best to take Cordelia’s head clean off her shoulders._

_They sparred for a good while as James switched continuously from practicing with his own daggers to watching them and shouting out helpful or misleading advice in an apparently random pattern. When they finally came to a stop, both girls were out of breath and covered in a healthy number of fresh bruises. Then, after a quick break for water and applications of various runes, Cordelia went up to the rafters to work on her footwork while James and Lucie squared off together._

_The two Herondales were, as always, a captivating blur of nimble feet and swift blows and Cordelia found herself watching them more than actually practicing. Not many brother and sister pairs sparred – Alastair and Cordelia, although trained together had been very rarely allowed to actually go against each other and never since Alastair had returned from the Institute, so much further ahead in training than Cordelia had been. But Will and Tessa Herondale had not differentiated much between their daughter and their son when it came to training and although James more often sparred with Matthew and Lucie with Cordelia, they had no problem going against each other when it came down to it._

_Even if it often seemed that James went a little easier on his sister than he perhaps should. As became obvious after Lucie easily blocked a blow and swept him onto the ground with a very well-timed sweep of her leg before pouncing on him with her axe blade precariously close to his throat._

_Cordelia couldn’t help the giggle that broke free from her at the sight of her fiancée sprawled onto the ground with Lucie’s small body pinning him down. It didn’t take long for the other girl to join in and for even James to let out a self-depreciating laugh as he sat up, carefully pushing his sister off of him. They called it quits after that and Lucie and Cordelia left James to get cleaned up and changed back into their normal clothes before meeting with him and their parents for a midday meal._

_Will was animated as ever and lunch was a raucous affair of laughter and light conversation and Cordelia found herself still smiling as she bid her future in-laws goodbye before allowing James to help her up into the Herondale carriage. Lucie had decided to join Cordelia in the short trip back to her home as there was a book of Persian poems translated into English in the Carstairs library she wanted to borrow and, after a few pointed looks from his father, James had volunteered to escort them so it was a very happy trio that the carriage carried back home._

_So involved in their rousing conversation about whether or not Lucie should include a character dying of Demon Pox in her next installment of ‘the Beautiful Cordelia”, the actual Cordelia did not have time to dwell on the possibility of what awaited in her home._

Had she dwelled, she might have come up with some excuse for having the Herondale siblings stay outside while she checked the home and saved quite a few people from a great deal of embarrassment.

But she did not dwell and thus, no one was spared.

_Once the carriage came to a jolting stop outside the Carstairs home, James hopped out easily and helped both girls down and they all offered thanks to Cyril before Cordelia led them into the house. At first, nothing seemed out of the ordinary. Her parents weren’t due home yet and, as Elsie and Imogen always chose to do the shopping in the afternoon together, the only person she expected to be home was Alastair, presumably still in the study or perhaps his room or the library. She nearly called for him – Tessa had given her some lovely tarts that Alastair would absolutely love – but a muffled thump coming from the parlor stopped her just in time._

_Alastair, apart from when he was playing the piano, was a remarkably quiet person. He did not make much noise by himself. He definitely did not make a habit of crashing into walls by himself, which was absolutely the sound Cordelia had just heard. And – Cordelia realized with a barely repressed shudder of dread – it was_ absolutely _the sound James and Lucie had just heard._

_“What was that?” James whispered, one hand already clenched loosely around a sizeable dagger as he turned toward the sound. When exactly he had drawn it, Cordelia had no idea, but he was definitely prepared to use it._

_Cordelia had a pretty good guess as to what that noise was, although Alastair throwing Thomas against the wall sounded surprisingly lighter in the middle of the day than it had in the dead of night, and she was absolutely not about to allow her brother to be discovered by James. Fiancé or not, James was_ not _entitled to her brother’s or Thomas’s secrets. “It was nothing, I’m sure.” She whispered too quickly, reaching out a hand to catch at James’s wrist. She caught Lucie’s gaze over his shoulder and quickly mouthed “Thomas!” before James turned back to look at her._

_“That wasn’t_ nothing _, Daisy.”_

_“Oh, probably someone left a window open and a draft knocked something down!” Lucie murmured quickly, reaching out and grabbing hold of her brother’s sleeve. Cordelia was so glad that her parabatai-to-be had caught on so quickly._

_“That wasn’t the sound of something small falling.” James whispered back, looking at his sister as though she had gone mad. “We’ve got to investigate. It could be someone in the house!” With that said, James brushed off both girls’ hands and began a slow, cautious creep to the parlor. If it weren’t such an awful moment, Cordelia would have been amused at how similar her and James were in these types of situations. Unfortunately for her, she knew_ exactly _how this situation was about to end and it was with the air of someone trying desperately not to let a tragedy repeat itself that Cordelia quickly followed after him, inwardly unleashing a torrent of her brother’s finest swears._

_“It really isn’t something you want to see!” Cordelia hissed desperately, catching James’ wrist once more. James might have heeded her words – the tone in her voice alone was enough to give him pause – if there hadn’t been another soft thump accompanying them. Without hesitation, James burst into the room, dagger raised protectively, and Cordelia, still holding tight to his wrist, was unwillingly drawn forward with him. The sight that greeted them was enough to stop James right in his tracks and even surprised Cordelia into temporarily freezing._

_She had assumed, given her past experiences with her brother’s and Thomas’s exploits, that it had been Thomas thrown against the wall. But the sound had been quieter, not because it wasn’t the dead of night, but because it had been her brother’s considerably smaller body against the wall this time, his head pushed up to reach Thomas’s mouth and his back arched obscenely as the taller man ran possessive hands down the small of his back before cupping -_

_Behind her – because of course her best friend had followed them into the room even though she knew what was on the other side – Lucie choked off something that sounded suspiciously like a laugh and that, rather than James throwing himself into the room, was what alerted Thomas and Alastair to their sudden crowd._

_Thomas’s hands dropped from Alastair’s body as though he had been scalded but he did not move away from the smaller man or turn to face them. In fact, from the side of his face that Cordelia could see, he had his eyes tightly closed and seemed to be whispering a hurried string of words under his breath, his entire face entirely red._

_“Really?” It was Alastair who broke the silence, peering over Thomas’s shoulder with a surprising amount of control despite the flush of his cheeks and the mussed mess of his hair. Cordelia realized with a jolt of dull horror that, not only was the dark purple waistcoat he’d been wearing when she’d left nowhere to be seen, but the top two buttons of his shirt were completely undone. Either they were farther along than they normally were when Cordelia caught them or Thomas, despite always appearing as the shyer, more prone to blushing and embarrassment of the two, was more efficient at getting to the main event of their affairs._

_Whatever the main event was – Cordelia had tried asking Matthew a few basic questions but it was hard to ask anything without getting in to_ why _she wanted to know and Matthew was far too suspicious as it was. And Anna, the one time Cordelia had asked her over tea at her flat, had brushed off Cordelia’s inquiry with a simple explanation that whatever men got up to in the bedroom with women didn’t even interest her, let alone what they got up to with other men._

_But now was not the time to get lost in her own thoughts. James was still standing next to her, his mouth open and eyes wide in pure shock, staring straight at Thomas and Alastair. She had to get him out before this situation got any worse. “I tried to tell him to stay out!” She told her brother – her voice was surprisingly casual sounding, even to her - before putting a hand on James’s chest and pressing firmly against him. Still too shocked to speak, James obediently began to take several steps back and they started towards the doorway with Lucie following closely behind._

_“Really sorry about that!” Lucie called over her shoulder, giving the two boys a little wave and a friendly smile. “Please feel free to finish up, we won’t be coming back!”_

_“Lucie!” Cordelia hissed as Alastair bit out a surprised laugh and Thomas slammed his head against the wall with a little groan of exasperation. “If you feel the need to continue, kindly take it to your bedroom, Alastair!” She added over her own shoulder as she gave James one final push and they made it out into the entrance way._

_“Thomas and_ Alastair _?” James finally spoke. He didn’t sound angry or upset, just very, very surprised and so, rather then drawing herself up to give a great big lecture to her fiancé, Cordelia just let out a drawn-out sigh._

_“_ I _did tell you it wasn’t something to be investigated, James.”_

_She would save the lecture on how Thomas and Alastair both cared deeply for and deserved each other and how James, regardless of how unfriendly Alastair and him had been to each other in the past, better not do anything to jeopardize their relationship for when James had regained the full ability to speak. At the very least, James now knew better than to just casually investigate every creak and bump that sounded in the Carstairs home._

_Which left her the time to focus on how there was absolutely no way getting caught a fourth time was an accident._

_Her brother was up to something and, for the sake of her sanity, she needed to find out what it was._

Which is what led her to this exact moment, marching into the Devil’s Tavern with Jamie and Lucie at her heels. 

Her day had started bright and early. She had breakfasted with her parents and her brother, just as she had done after every incident before the last, but when it came time to clear the table – the moment her brother normally slipped out to attend to whatever he was doing that day, Cordelia left her plates at the edge of the table and sidled after him.

“You are to be at the Devil’s Tavern at noon with Thomas.” She had told him without preamble. He had given her a look but Cordelia flatly ignored it. “James and Lucie will be with me.”

She had slipped past him once she had finished speaking and headed out of the door without another word. It hadn’t taken long to summon their carriage driver, a genial young man named Frederik Bauer, and she had been off to the Institute before her brother had probably even fully registered her words. James and Lucie had been waiting for her in the parlor of their home, as they had agreed on the day before and without preamble, Cordelia had begun speaking.

“As you both have realized, Alastair and Thomas are engaged in an intimate relationship. They have been for at least a month now, and from the many, many things I’ve seen, it appears quite serious.” James had opened his mouth, perhaps to express surprise once more, but Cordelia swiftly went on. “They seem very happy and quite – _compatible_ with each other and I will not entertain any words otherwise. However, they have made an unfortunate habit of being – _affectionate_ in fairly public places. I have reason to believe that my brother might be doing this on purpose, and I need your help putting a stop to it.”

Her words had been met with silence for a moment. And then: “You think they are doing it on _purpose_?” James’s voice had been filled with shocked disbelief. Cordelia had just nodded.

“Why _would_ they, though?” Lucie, who had heard this theory before already, had asked calmly as she reached forward for the teapot she’d brought in and began pouring a cup for all three of them.

“I may have insinuated Alastair enjoyed being caught in precarious situations after I caught him and Thomas the first time,” She responded with careful dignity.

“You did _what?”_ James had demanded and after a good deal of explaining in which Cordelia had to very delicately explain that she had caught Alastair once before Thomas without naming Charles, both the Herondale siblings had agreed that yes, torturing Cordelia over the month did indeed seem like a very Alastair thing to do. And then they had asked what Cordelia was planning to do to get her brother to finally ease up.

“What I should have done in the first place,” Cordelia had responded simply, “Apologize.”

Her words had, of course, set of another wave of questions from both of them and a fair bit of disbelief from Lucie who, as a fellow little sister, did not like the idea of just _apologizing_ to an older brother. But Cordelia had held firm.

“I believe I hurt Alastair’s feelings, when I fought with him that night. I thought he had brushed my words aside and I allowed myself to ignore what I had said. But that was wrong, and even if Alastair’s reaction has been very unfortunate for all of us, I am the one who should apologize first. And I believe you two should come with me so that you can tell them you approve of their relationship.”

“Why do we need to do that?” James had asked then. “I’ve never told Math or Anna that I approved of their relationships and it’s never been a problem.”

“It isn’t because they are both men,” Cordelia had responded immediately, even though that would undoubtedly be the very part most people would have a problem with. “It’s because it’s Alastair – who you spent a great many years abhorring – dating Thomas – one of your best friends and practically your cousin. My brother can be very insecure about things and him knowing that you both approve of him dating Thomas will go a long way to making them both more comfortable. My brother deserves to be happy; Thomas makes him happy; therefore, I will not allow anything or anyone to mess that up. Hence, I will apologize so that they stop engaging in passionate embraces in risky places and you and Lucie will give them your blessing so that they know that the few people who do know about them approve.”

Her words had easily swayed James – Herondales were all hopeless romantics at heart, after all. It was in their blood. And Lucie had needed no convincing at all on the matter as she was not only a romantic at heart, but also had a very healthy-sized fascination with forbidden or secret loves. And so they had agreed to accompany her to the Devil’s Tavern, where she hoped to settle all this once and for all.

Unfortunately, as became apparent, the moment right after Cordelia, James, and Lucie had stepped into the Devil’s Tavern, solving this situation and getting all their lives back to normal was going to be a lot more complicated than Cordelia had anticipated. For, coming in through the door just after them with a timing that was nothing short of demonic, were Matthew and Anna, both dressed exquisitely as usual, and Christopher, who had a very suspicious burn hole in the bottom corner of his waistcoat but otherwise seemed relatively unrumpled.

Cordelia allowed herself just one moment to mutter a quiet but heartfelt swear under her breath before turning to the trio. “Hello,” she called, trying to put on her best casual smile. “We didn’t know you’d be here, today.”

Her voice sounded a bit too high to herself, but it seemed that none of the other three had noticed. Matthew smiled widely at her as Anna slipped past to chat up one of the barmaids and Christopher pulled out a book from seemingly nowhere and began reading right behind him. “We were having tea at Anna’s when she decided she was in the mood for a quick drink.” He shrugged lightly. “I think she may be having some difficulties with Ariadne out of town with her parents, but she won’t admit anything and I rather value this new waistcoat, so I haven’t asked.”

“Oh, she’s definitely pining.” Christopher piped out from behind his book. Cordelia hadn’t even known he was paying attention.

“Do you think drinking is a good idea for her, then?” Lucie asked from next to Cordelia, peering at her cousin as she leaned casually against the bar, all slim limbs and graceful elegance.

“I cannot say if it is good for _her_ , but a drink or two to mellow her out is certainly good for the rest of us. She nearly threw a teacup at Christopher earlier. And she had just poured it.” Matthew explained, his cheerful belying the serious nature of his words. Cordelia had to admit that did sound rather dire. It usually took a lot to visibly faze Anna and a considerable deal more to get her to be angry at her younger brother. She was far more likely to be angry for Christopher than at him.

“Well, that does sound pretty bad. I trust you and Christopher will watch over her, then?” James asked, clapping a hand on Matthew’s shoulder. It was just a shade too dismissive – Matthew’s smile fell into a look of suspicion, as though it had just dawned on him how strange it was for James to be frequenting the Devil’s Tavern in the middle of the day with his fiancée, little sister, and none of the Merry Thieves.

“What are you guys up to, then?” He asked. Cordelia quickly considered their next best course of action. She couldn’t allow Matthew, Christopher, and Anna to be upstairs when she met with Alastair and Thomas – it would look like she had planned to expose them. But she also couldn’t lie – Matthew was unreasonably good at figuring out lies and he would just follow them upstairs to eavesdrop. And then Anna would follow him too, because she loved a good secret, and Christopher would follow without even realizing they were going to eavesdrop on someone because he was distracted.

She would have to tell him a mostly-truth then. “We’re going to meet with my brother upstairs. He’ll be here soon, so if you’ll excuse us, Matthew, Christopher.” She turned to leave up the stairs before Matthew could ask anything else, hoping James and Lucie would follow her immediately, but Matthew was too quick.

“Why don’t we join you then? Anna can take her bad mood out on Alastair while we have an enjoyable afternoon.” He said, and there was something dangerously like suspicion undercutting his cheerful tone. Cordelia inwardly cringed but turned around with a wide-eyed, innocent expression on her face.

“Oh, I wouldn’t ask you for that. I know you and Alastair still don’t quite care for each other. I wouldn’t want your afternoon to be soured with any unpleasant disagreements.”

“Nonsense!” Matthew said, a winning smile Cordelia didn't believe for a minute firmly in place. “Alastair and I have been getting on just fine now that he’s not nearly as much of an unsufferable prat. I was only mostly joking about Anna taking her bad mood out on him. They get along fairly well, maybe he’ll be able to cheer her up about Ariadne.” Anna and Alastair did get on along better than Alastair and any of the others, barring Thomas. Cordelia was pretty sure it was because Ariadne and Alastair were quite good friends, which given their particular history of being involved with the same man who just so happened to be Matthew’s older brother, was not something the others understood very well.

She made to argue once more, but it was too late – Anna had returned, a drink in hand, and Matthew gave her a bright smile and told her they were going to their room. Then he sidled past Cordelia and began walking up the stairs, Christopher absently following behind him and leaving her and the others no choice but to follow him.

Cordelia had not expected her brother to be at the tavern yet – she wasn’t even completely sure that he would be coming at all, which was the only reason she did not try and force Matthew, Christopher, and Anna back downstairs. She figured that once Alastair and Thomas arrived, she could come up with some excuse to speak with her brother privately and then James and Lucie could speak with him and Thomas at a later date, away from curious eyes. It wouldn’t be all that strange, after all, for all of them to spend the afternoon together. She might even be able to smooth over Matthew’s suspicious edges and keep him from questioning her brother or Thomas for at least a while longer.

It was a good plan, especially considering she had only the few moments it took to climb the stairs of the Devil’s Tavern to come up with it. Unfortunately for her, when Matthew opened the door to their private room wide enough that everyone behind him could peer into it, it was made abundantly clear that Alastair had indeed come to the tavern and that he was very much not alone.

Cordelia should have really expected it at this point. She knew her brother had been torturing her the entire month with these exact same situations, after all. She _really_ should’ve expected it. But it still took her by surprise to see Thomas sitting in an overstuffed armchair, his arms loosely wrapped around the waist of her brother. Alastair was draped over his lap casually, one hand lifted up to gently cup Thomas’s face as they shared a lazy kiss.

At the very least, she reflected with a sort of casual detachment as she heard James give a sharp intake of breath beside her, they were both still entirely clothed and no one’s hands were heading to unmentionable places. In fact, their kiss had a softness to it that the others definitely hadn’t.

It was the type of kiss only people who cherished each other shared and it would have been quite a sweet sight if Matthew hadn’t taken that exact moment to loudly cry out, “ _I knew it!”_ while pointing at the pair.

Much to Cordelia’s surprise, they did not jump or start cursing as they had done every other time she’d caught them. Instead, Alastair simply turned his head and shot Matthew an unimpressed look without bothering to remove himself from Thomas’s lap. Thomas, true to form, blushed slightly but made no move to separate from Alastair. There was silence in the room for a moment following Matthew’s statement until Anna, apparently unaffected by walking in on her cousin, pushed her way through the small group crowded at the doorway and strolled into the room.

“Honestly, Matthew. It took you this long?” She asked casually, propping herself onto the arm of the chair right next to the couple before offering the couple a sly smile. Alastair smiled back, a devilish spark in his eyes, and Cordelia had officially seen enough.

“Okay, what _on Earth_ is going on here?” She demanded, storming into the room. “You _knew_?” She asked Anna who gave a small shrug and a grin in response.

“ _You_ knew?” Matthew, who had followed into the room along with James who looked mostly confused at the strange turn of events, Lucie who looked mostly delighted at the strange turn of events, and Christopher who hadn’t even looked up from his book at the strange turn of events. Cordelia threw her hands out in exasperation.

“How could I not when every other day I catch them at some –“ she stopped herself just in time, took a deep breath, and turned back to Alastair and Thomas with visible effort. “Can one of you please explain to me _what_ is going on? I thought you were letting me catch you on purpose to teach me a lesson but why on Earth would you want –“

“You thought we were doing it on _purpose_?” Thomas interjected, a bit of horror in his voice.

“Too be fair, you did plan _this_ one,” Anna said, far too casually, over the top of her glass.

“Well – alright, yes. But that’s completely different –“

“Is it really, though?” James said, staring at his friend and Alastair. Thomas flushed even redder but Alastair just casually leaned towards Anna who offered him her drink without a word. “Why would you plan for us to walk in on you –“ he seemed to struggle to find the words to describe the situation. Cordelia couldn’t blame him – she still didn’t know the right terminology although it seemed that Anna was far more interested in what two men did together than she had let on over tea.

“Well.” Thomas’s face was entirely red now. “I was trying to figure out a way to tell you all that we –“ he paused briefly before adding, “had an agreement.” So they _did_ use the same terms. At least that was one mystery Cordelia could lay to rest. “But it was really difficult to find the words. We all had some issues with Alastair in the past –“ That was rather an understatement. Cordelia still remembered the month straight when Alastair and any of the Merry Thieves hadn’t even been able to stay in the same room without someone storming out – “and I was worried that you guys wouldn’t be okay with me seeing him –“

“We would never get in the way of you seeing someone you truly cared about!” James interjected immediately. Matthew nodded emphatically and Thomas offered both of them a smile.

"You don’t know how glad that makes me,” he told them honestly. “But I had no way of knowing that at the time and so it was hard to come up with the courage to say anything. But then, Cordelia walked in on us. And then Lucie and Cordelia walked in on us and then James, Lucie _and_ Cordelia walked in on us. And Anna already knew because – well, I don’t actually know how she knew.” Thomas shot a questioning look at his cousin who simply smirked.

“I know everything.” She responded cryptically and no one could argue against that.

“Plus I told Ariadne and that girl tells you everything.” Alastair added and Anna shrugged.

“True.”

“Why did you tell Ariadne and not Cordelia?” Lucie asked, her curiosity evident. It was a fair question – Cordelia would have asked it herself if she hadn’t already known about Alastair and Ariadne’s unusual connection.

Alastair seemed to momentarily break his cool and coughed delicately before saying, “We’ve shared similar relationship problems.” Cordelia barely refrained from letting out a very unladylike snort. “So now we confide with each other." Alastair continued. "For example, I know Anna is an incorrigible bed hog.”

Anna nodded in agreement. “And I know that Thomas –“

“ _And_ Matthew already suspected –“ Thomas jumped in quickly, his cheeks fiery, “so we knew it was past time to say something. But we couldn’t really decide how to go about it and so when Cordelia told us to meet here today, we decided to go to Anna for help. And when we explained the situation, she told us that, since we seemed so good at letting people walk in on us, we should just tell you all that way. So we did.” Thomas finished with his cheeks still bright red. But he shared a brief, gentle smile with Alastair at the end and if anyone – particularly Matthew and Christopher who appeared to be the last to officially know – were angry with them before, there was no way they still were after that smile. Cordelia herself could almost forgive him anything, when he smiled at her brother like that.

“For the record, I meant it in jest.” Anna told them. “But Alastair is nothing if not a little demon and he latched onto the idea with frankly concerning enthusiasm. He convinced me to send notes to you both,” she gestured at her brother and Matthew with her half-empty glass. “inviting you for tea and then he hauled Thomas off to this fine establishment for some basic canoodling until someone walked in on them.” 

"So you aren’t actually pining about Ariadne?” Cordelia blinked in surprise at hearing Christopher speak for the first time since entering the room. She had honestly thought he hadn’t been paying attention at all and they would have to explain the whole thing again when he finally looked up from his book. But Christopher was peering over his book now, apparently unfazed by the realization that Thomas and Alastair were together, and staring at his sister with a confused expression.

“I don’t pine, Christopher.” Anna responded haughtily. Christopher’s expression turned even more bewildered.

“Then why did you nearly throw your cup at me?”

“Because you were ignoring me _pretending_ to pine!” Anna answered and Cordelia, feeling like they were getting rather off track, turned back to her brother who was still sitting on Thomas’s lap with the air of a prince on his rightful throne.

“So those moments were really just accidents?” Cordelia asked him quietly, drowning out the rest of the conversation around them. It was honestly the hardest part of the whole situation to wrap her mind around. She had been so _sure_ Alastair was messing with her.

“Do you honestly think I would have _wanted_ you to see any of that?” Alastair answered back immediately. “I know you and James are being perfectly respectable and _not_ being intimate before marriage, but surely even you know that most people do not desire their sibling interrupting them all the time?”

“Well, you have been petty before!” Cordelia answered defensively, her cheeks warm at the mention of her and James.

“When we were _children_!” Alastair responded back immediately but there was little heat in his voice. Not even Alastair could find it in himself to be annoyed in view of how easily the group accepted him and Thomas. “Anyway, you won’t have to worry about walking in on us anymore.” He added before Cordelia could give him another retort. “The flat underneath Anna’s is being let out and I’ve already spoken to Father about purchasing it.”

“You’re moving _out_?” All other thoughts left her mind suddenly at the idea of Alastair being gone. She had lived without him before, of course, but whenever he was at the Academy there had always been the promise of his return. Throughout all their moves and their lonely childhoods, Alastair had always been around for her and it was disconcerting to be suddenly confronted with the idea that it would not always be like that.

Alastair’s expression seemed to soften at Cordelia’s words. “After the baby is born, yes. Thomas has agreed to live with me – we can start a life together, I think. And you’ll be living with James soon, anyway. It’s the right time.” Cordelia bit her lip at her brother’s soft words. She knew he was right and a large part of her rejoiced for him – when she had first learned about Alastair and Charles, there had seemed no way for him to have a happy ending with the person he loved. There was no way she could be anything less than ecstatic to know that was no longer the case. But another part of her, small but loud, mourned the change. It was a chapter closing in their lives, the true transition from childhood to adulthood – as excited as Cordelia was to marry James and as excited she was to see her brother live his life as openly as he could, she was sad to say goodbye to what they used to be. It was sad to think that Alastair would no longer be living just a few feet away from her at all times.

“I won’t be far.” Her older brother said, his voice quiet enough not to draw the attention of any of their friends – all of whom had somehow gotten swallowed into a lively discussion of older and younger siblings – save for Thomas, who had enough tact not to draw attention to himself as the siblings had a private moment. “You can visit whenever your Herondale gets taxing.” Cordelia let out a little laugh at that and Alastair smiled before adding, “Just make sure you knock first.” Cordelia laughed even louder at that, a bright, contagious sound that Alastair soon joined in with.

It had been a strange month for Cordelia – quite possibly the strangest of her entire life and that included stepping into a demonic dimension to follow after the love of her life – but she had to admit to herself, as she stood in the Devil’s Tavern, surrounded by the most cherished people in her life and about to embark on the next grand adventure alongside her brother, it had been entirely worth it.

Just as long as Alastair and Thomas remembered to actually close and lock their flat door.

**Author's Note:**

> This was entirely based on the fact that Alastair had a secret love affair with an engaged man and still thought it was a good idea to make out in a freaking parlor. Was this at all historically accurate or accurate to how it will probably be in the series? No. Do I care? Also no. This was supposed to be short and cute it was but it got super away from me. I had a lot of fun writing it though and I hope you enjoyed reading!


End file.
